Sluice Mat
 
It is important to demonstrate different types of sisal fabrics and carpets. The best carpet used in ASM operations is the 3M Nomad Dirt Scraper Matting, especially the type 6050 (medium traffic with backing) which consists of a coiled vinyl structure; type 8100 (an un-backed version) can also be used. Nomad is usually recommended for relatively coarse gold, but can also trap fine gold efficiently. The price of Nomad carpets in ASM sites can reach up to US$ 150/m²; alternately, a Nomad type vinyl loop carpet is available from manufacturers in China for a fraction of this price. The Brazilian company Sommer (subsidiary of the German company Tarkett Sommer) sells 2 types of carpets widely used by Brazilian ASM: "Multiouro Tariscado" (which is good for gold of medium sized rice grains) and "Multiouro Liso" (which is good for - 0.15 mm gold). These carpets can cost around US$ 10 to 15/m². None of these carpets are easily accessible to ASM in Africa. Sisal fabrics however, can cost as little as US$ 3/m², and are available in most African countries; depending on the type, they can be used for coarse, medium and fine gold recovery. It is a matter of trying different types. Raffia mats have been used in Zimbabwe for fine gold concentration. This definitely must be further investigated and collaborative tests can be done with the miners to establish the ideal type of sisal cloth.
Magnetite, a mineral commonly found in gold-ore deposits, is held by the magnetic sheeting, and forms a fine-grained corduroy-like trapping mechanism on the sluice floor. These inserts can be available in any size, but they are relatively expensive. For example, Cleangold® can manufacture a 60 x 50 cm insert for around US$ 165 (in USA). The main advantage of this sluice is the high concentration ratio. Gold becomes trapped in a magnetite layer which can be easily scrapped and washed into a pan. Using a magnet, the magnetite is removed and a high grade of gold concentrate is obtained. In many cases the use of mercury to amalgamate the concentrate is not necessary. However, as the magnetic separation isn’t always 100% efficient, and the concentrate tailings can carry some gold, so amalgamation or even leaching of the concentrates is recommended. In one test comparing the Cleangold® sluice with a centrifugal concentrator, the sluice obtained slightly better gold recoveries than the centrifuge. In a recent field test in Venezuela conducted by UNIDO, tailings from hammer mills and Cu-amalgamating plates were passed without regrinding through a 60 cm long Cleangold® sluice box. About 11% of gold in the tailings was recovered and the concentrate analyzed 2850 ppm Au. The Cleangold sluice can also take advantage of the fine pieces of steel released from hammer and ball mills. They are also concentrated on the magnetic sluice and play the role of magnetite. 
MINTEK (South Africa) has devised interesting sluice boxes (strakes) with rubber mat glued to it. Black ribbed vinyl mats are also useful to recover gold; they are easy to clean and cost in USA about US $15/m².

 

African pattern rubber riffle mat

Miners moss sluice carpet is the preferred matting for gold recovery. The moss traps and holds gold inside loosely woven vinyl fibers which are easily cleaned to recover the black sand concentrates and your gold. Choose the thick type that is backed so the gold cannot work through. This product can be purchased online from a prospecting supply shop. If you are planning to install several traps, this may be a bit expensive - if so, you can use the cocoa-fiber mats and apply your own backing as described below.
Thick cocoa-fiber door mats (These can be purchased fairly reasonably if you can catch them on sale at your local hardware store - or research and find a source to purchase this material by the square yard.) These cocoa-fiber mats are commonly used as entryway matting, because they do a great job of grabbing and holding the dirt people track in on their shoes. As such, it's perfect for catching and holding the heavies as they flow down your sluice trap.
Construction Adhesive  - The adhesive is used to seal the bottom of the cocoa-fiber to prevent the black sand and gold from working through the mat and escaping out of the bottom. I think that the product “Liquid Nails” works very well. Just spread it thickly on one side of the mat and allow to dry. This can be found at any hardware store. There are also spray-on products that are designed to prevent rugs from sliding about - repeated spray applications of this rubberized material will seal the back of your mat and still remain fairly flexible.
Plywood or metal material to build a sluice box configuration. Metal works best as wood tends to rot or warp when submerged in water. 
 
 
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Sluices